WEBVTT Kind: captions; Language: en 00:00:00.000 --> 00:00:25.000 [...] 00:00:34.001 --> 00:00:39.000 The lights are dimmed, the projector is running, the classroom has become a 00:00:39.000 --> 00:00:46.000 setting for use of a very effective teaching tool, the classroom film. Yet what 00:00:46.000 --> 00:00:50.001 these young people learn and how well they learn it rests largely with how the 00:00:50.001 --> 00:00:57.000 film is used. It does work. We've constructed an electric motor from a few simple 00:00:57.000 --> 00:01:02.001 materials. Let's review what happens by looking at a diagram. Here is the 00:01:02.001 --> 00:01:09.000 permanent magnet. Like all magnets it has a north pole and a south pole. Here's 00:01:09.000 --> 00:01:13.000 the block of iron with the coil of wire around it, an electromagnet. 00:01:14.001 --> 00:01:21.000 The coil of wire is attached to wires leading to a dry cell. When current starts 00:01:21.000 --> 00:01:28.000 to flow, the coil becomes an electromagnet with north and south poles. These 00:01:28.000 --> 00:01:32.000 poles of the electromagnet are attracted by the poles of the permanent magnet and 00:01:32.000 --> 00:01:39.000 the block of iron turns. If we reverse the direction of the current in the coil 00:01:39.000 --> 00:01:43.000 by changing the dry cell connections, the north and south poles in our 00:01:43.000 --> 00:01:48.000 electromagnet reverse. This puts two north poles together and two south poles 00:01:48.000 --> 00:01:53.000 together. Since light poles repel each other, the electromagnet rotates until 00:01:53.000 --> 00:01:58.001 opposite poles are attracted to one another. If we add the automatic switch to 00:01:58.001 --> 00:02:03.001 our diagram, it will look like this. Now if the wires are connected to the dry 00:02:03.001 --> 00:02:07.000 cell, the motor will continue to rotate in one direction. 00:02:13.000 --> 00:02:18.001 For a science class concerned with how an electric motor works, a classroom film 00:02:18.001 --> 00:02:24.000 has illustrated a complex process in simple understandable terms. The film, as is 00:02:24.000 --> 00:02:29.001 often true, has proved itself an effective and valuable teaching aid. This is 00:02:29.001 --> 00:02:34.000 particularly true when the film has been carefully selected for content and when 00:02:34.000 --> 00:02:38.000 the students have been correctly prepared for viewing the film. Activities which 00:02:38.000 --> 00:02:43.000 follow the film are also important. Activities such as a post-film discussion. 00:02:44.000 --> 00:02:48.000 Now can someone explain to me the function of one of the basic parts of the 00:02:48.000 --> 00:02:55.000 electric motor? Danny. Well without that automatic switch, the part called 00:02:55.000 --> 00:02:59.000 the commutator, the motor wouldn't make a complete revolution. Do you all agree 00:02:59.000 --> 00:03:04.001 with Danny's statement? George. Yes I do because on the diagram you could see 00:03:04.001 --> 00:03:08.000 that the commutator reverses a current. If it didn't, the motor action would 00:03:08.000 --> 00:03:13.000 stop. All right now from what we've seen in the film and talked about, can 00:03:13.000 --> 00:03:17.000 someone give me the definition of a commutator? Sharon, give me your definition. 00:03:18.001 --> 00:03:24.001 A commutator is a device for reversing the direction of a current. The film has 00:03:24.001 --> 00:03:29.000 been used to convey information and to stimulate deductive thinking. This kind of 00:03:29.000 --> 00:03:33.000 discussion of content is as much a part of using a film as the actual showing of 00:03:33.000 --> 00:03:39.000 it. For a film however good it may be is still only a teaching tool and depends 00:03:39.000 --> 00:03:45.001 for its greatest effectiveness on how it is used by the teacher. Effectives of a 00:03:45.001 --> 00:03:50.000 film begins days perhaps even weeks prior to the showing when the teacher selects 00:03:50.000 --> 00:03:54.001 the film. The director of her local instructional material center can often 00:03:54.001 --> 00:03:59.001 provide helpful advice about which of several films in the same subject area will 00:03:59.001 --> 00:04:06.001 best suit the teacher's purpose. Of course one may have 00:04:06.001 --> 00:04:10.001 to rely on the resume in a catalog to determine a film's content as well as its 00:04:10.001 --> 00:04:17.000 running time and the grade level for which it was intended. The important thing 00:04:17.000 --> 00:04:22.000 at this point is that selection is not a hit or miss affair but keyed to a lesson 00:04:22.000 --> 00:04:27.001 plan and made on the basis of the best information available about a film. The 00:04:27.001 --> 00:04:32.000 next step you as the teacher take in using a film is to become familiar with it 00:04:32.000 --> 00:04:37.000 yourself. If the film is available to you for only a short time you may have to 00:04:37.000 --> 00:04:41.000 limit your own preparation to studying the teacher's guide for the film if it is 00:04:41.000 --> 00:04:48.000 available. Here you will find usually a more complete description of the 00:04:48.000 --> 00:04:55.000 film's content than is possible in a catalog or the 00:04:55.000 --> 00:05:01.001 film. Comments from previous users of a particular film if they are 00:05:01.001 --> 00:05:08.001 available are also helpful. An ideal way to study 00:05:08.001 --> 00:05:13.000 a film and prepare to use it with your class is to preview it with pencil in hand 00:05:13.000 --> 00:05:18.000 taking notes as the film progresses. It can be a real help to have one or more of 00:05:18.000 --> 00:05:22.000 your students in the preview room with you. As they watch from a viewpoint which 00:05:22.000 --> 00:05:26.001 is different from yours they will detect new or unusual words or situations which 00:05:26.001 --> 00:05:30.001 may require explanation before the film is shown to the group. They may also 00:05:30.001 --> 00:05:37.001 reveal interests a teacher may use to motivate the entire class. Well Billy was 00:05:37.001 --> 00:05:42.000 there anything you didn't understand? Well I don't understand why the farmers and 00:05:42.000 --> 00:05:46.000 cattlemen had to fight so much. Why couldn't the farmers just settle and plant 00:05:46.000 --> 00:05:51.000 their crops in areas where the cattlemen were located? How about you Mary? Any 00:05:51.000 --> 00:05:58.000 words you didn't understand? Well blooded something, blooded stock I think 00:05:58.000 --> 00:06:03.001 it was. Creative teachers have many ways of developing class readiness for seeing 00:06:03.001 --> 00:06:09.000 a film. Preparation often starts the day before unusual words may be defined 00:06:09.000 --> 00:06:15.000 beforehand. You recall that yesterday we talked about the problems of settling 00:06:15.000 --> 00:06:20.000 this large area of our country known as the Great Plains. Today we're going to 00:06:20.000 --> 00:06:25.000 see a film that shows us those problems very clearly. Of course when the Great 00:06:25.000 --> 00:06:30.000 Plains were being settled in the 1850s and 1860s the movie camera had not yet 00:06:30.000 --> 00:06:35.001 been invented. So in this film we get the story as we look at famous paintings 00:06:35.001 --> 00:06:40.001 and drawings made by artists who were there at the time. Now Kathy do you recall 00:06:40.001 --> 00:06:46.001 the problem about the plains area that we discussed yesterday? Well there was 00:06:46.001 --> 00:06:51.000 constant fighting between ranchers and farmers over the use of land so neither 00:06:51.000 --> 00:06:53.000 of them could become really prosperous. 00:06:53.001 --> 00:06:58.000 And we decided that this situation kept many people away who might otherwise have 00:06:58.000 --> 00:07:03.000 come and helped to settle the Great Plains. Yes very good summary Kathy. Now in 00:07:03.000 --> 00:07:06.001 this film we're going to learn about some other problems that faced these people 00:07:06.001 --> 00:07:08.001 and what they finally did about them. 00:07:09.001 --> 00:07:14.000 Afterwards I want you to be able to identify and discuss the problems and to 00:07:14.000 --> 00:07:20.000 describe how the country's history. All right let's have the film. 00:07:23.001 --> 00:07:28.000 It wasn't like the days when cowboys fought Indians. Between cattlemen and 00:07:28.000 --> 00:07:33.000 farmers nobody had the what for to make the difference. Both had six shooters and 00:07:33.000 --> 00:07:37.000 both could use them. Peace depended it seemed on finding 00:07:37.000 --> 00:07:38.001 a cheap and practical fence. 00:07:39.001 --> 00:07:46.000 Some tried a thorny hedge. The OC's orange for fencing. And it was pig tight 00:07:46.000 --> 00:07:52.001 horse high and bull strong. But it took four years and more to grow. Others tried 00:07:52.001 --> 00:07:58.001 just plain old wire but cattle shoved right through it. And the search continued. 00:07:59.000 --> 00:08:02.001 The search for a fence that would combine the low cost of wire 00:08:02.001 --> 00:08:04.001 with the thorns of a hedge. 00:08:26.000 --> 00:08:32.001 In 1874 Joseph Farwell Glidden a 60 year old farmer was granted a patent for 00:08:32.001 --> 00:08:34.001 a barbed fence wire that worked. 00:08:35.001 --> 00:08:40.000 The following year Jacob Hage received a patent for his improved S barbed steel 00:08:40.000 --> 00:08:44.001 fence wire. Both methods were practical and inexpensive. 00:08:45.000 --> 00:08:49.001 The West got its fencing but the new fences blocked off the 00:08:49.001 --> 00:08:51.000 cattle trails to the railroads. 00:08:51.001 --> 00:08:54.001 And there were some who resisted the changes on the plains 00:08:54.001 --> 00:08:56.001 brought about by barbed wire. 00:08:57.000 --> 00:09:03.000 Some fenced off water holes forcing others to become fence cutters. But the 00:09:03.000 --> 00:09:05.000 bark of six shooters diminished. 00:09:05.001 --> 00:09:10.001 Laws were passed to protect both sides and in time barbed wire turned out to be a 00:09:10.001 --> 00:09:17.000 blessing to the native Texas longhorn. A tough mean 00:09:17.000 --> 00:09:21.000 ornery critter as tough on the table as he was on the range. 00:09:22.000 --> 00:09:26.001 With barbed wire fencing the cattlemen could separate their herds introduce 00:09:26.001 --> 00:09:31.001 blooded stock and supply the demand for better beef. Soon the great 00:09:31.001 --> 00:09:33.001 plains became a new land. 00:09:34.000 --> 00:09:40.000 The railroad the Colt revolver the artesian well the windmill new 00:09:40.000 --> 00:09:42.000 ways of farming dry land. 00:09:42.000 --> 00:09:48.001 And of course barbed wire enabled our country to settle the vast interior to turn 00:09:48.001 --> 00:09:53.000 what was once the great American desert into rich fertile farmland. 00:09:54.000 --> 00:10:00.000 Who can give me some reasons why the invention of barbed wire was so important 00:10:00.000 --> 00:10:01.001 to the development of the great plains. 00:10:03.000 --> 00:10:03.001 Jimmy. 00:10:05.000 --> 00:10:09.001 Well the barbed wire helped both farmers and cattlemen because they could keep 00:10:09.001 --> 00:10:11.000 the cattle where they're supposed to be. 00:10:12.000 --> 00:10:14.000 And the farmers could do more farming and less fighting. 00:10:15.000 --> 00:10:17.001 Yes and this was the only kind of wire fencing ever invented 00:10:17.001 --> 00:10:19.000 that could do the job wasn't it. 00:10:20.000 --> 00:10:23.001 Why didn't they build wooden fences. Karen. There wasn't any 00:10:23.001 --> 00:10:25.001 wood. Yes that's right Karen. 00:10:26.001 --> 00:10:29.001 Now I think it might be interesting to find out why there was no wood 00:10:29.001 --> 00:10:31.000 available in the great plains area. 00:10:31.001 --> 00:10:36.000 This will take some research. So Karen you Betty Tom and 00:10:36.000 --> 00:10:38.000 Alan prepare a report on this. 00:10:38.000 --> 00:10:40.001 We're all going to spend some time reporting on other 00:10:40.001 --> 00:10:42.000 aspects of this subject too. 00:10:43.000 --> 00:10:45.001 Who would like to find out more about the benefits the barbed wire 00:10:45.001 --> 00:10:47.001 fencing made possible for the cattlemen. 00:10:48.000 --> 00:10:48.001 Bob. 00:10:50.000 --> 00:10:53.000 Well I recall the film mention something about separating the 00:10:53.000 --> 00:10:54.001 herds and introducing blooded stock. 00:10:55.000 --> 00:11:00.000 I'd like to know more about this. Okay Bob you team up with George Bessie 00:11:00.000 --> 00:11:02.000 Elaine and Frank on that question. 00:11:02.001 --> 00:11:07.000 There are many ways to conduct post film activities profitably. The objective 00:11:07.000 --> 00:11:11.000 should always be to use the film as a springboard to learning 00:11:11.000 --> 00:11:13.000 understanding and creating. 00:11:15.000 --> 00:11:18.001 Assigning a research project on a topic related to the film will help the student 00:11:18.001 --> 00:11:23.001 to form relations of ideas concepts and facts and thereby provide 00:11:23.001 --> 00:11:25.000 creative learning experiences. 00:11:28.000 --> 00:11:33.000 In any review of effective use of classroom films we should not overlook the 00:11:33.000 --> 00:11:34.001 importance of physical details. 00:11:35.000 --> 00:11:38.000 For example proper arrangements for seating lighting 00:11:38.000 --> 00:11:40.000 ventilation and placement of equipment. 00:11:43.001 --> 00:11:50.000 Also if you plan to run the film yourself 00:11:50.000 --> 00:11:54.000 check ahead of time to make sure you are familiar with the projector and its 00:11:54.000 --> 00:11:57.000 operation how to thread it and how to operate the controls. 00:11:59.001 --> 00:12:04.001 Where these details are handled by a student projectionist it is still important 00:12:04.001 --> 00:12:08.001 for you to make sure that these arrangements are made beforehand. All these 00:12:08.001 --> 00:12:13.001 physical details may contribute or detract from the showing and hence they are 00:12:13.001 --> 00:12:20.000 relevant to the creative use you make of a film as a teaching tool. Remember 00:12:20.000 --> 00:12:25.000 also that since using a film is part of a creative process the steps you take 00:12:25.000 --> 00:12:27.000 reflect your own creative ability. 00:12:29.000 --> 00:12:32.001 The first point at which you put your creativity to 00:12:32.001 --> 00:12:34.000 work is in the selection of the film. 00:12:35.000 --> 00:12:39.000 Choosing it for your purposes on the basis of your evaluation of it for the 00:12:39.000 --> 00:12:40.001 effectiveness with your students. 00:12:43.001 --> 00:12:47.001 The second point is the key to all the steps following it your own 00:12:47.001 --> 00:12:49.001 preparation for showing the film. 00:12:50.000 --> 00:12:53.001 This is the point where you decide whether you will show the film all at one 00:12:53.001 --> 00:12:56.001 sitting or use only an excerpt which applies to the 00:12:56.001 --> 00:12:58.000 particular topic being studied. 00:12:59.001 --> 00:13:04.000 It is the point at which you make final plans for how to use this teaching tool. 00:13:06.001 --> 00:13:11.001 At the third point class motivation you develop readiness for viewing the film. 00:13:12.000 --> 00:13:15.001 This may be a simple procedure of telling your students the title of the film, 00:13:15.001 --> 00:13:20.000 why they are seeing it and some idea of what they are expected to learn from it 00:13:20.000 --> 00:13:24.000 or it may be as elaborate as using other teaching techniques over several 00:13:24.000 --> 00:13:26.000 periods leading up to the showing. 00:13:29.000 --> 00:13:34.000 Point four the showing of the film when the creative process is seemingly out of 00:13:34.000 --> 00:13:39.000 your hands still reflects your guiding role particularly if you decide to repeat 00:13:39.000 --> 00:13:42.001 the showing of the film or to shut off the projector at a certain spot 00:13:42.001 --> 00:13:44.000 for a predetermined reason. 00:13:44.000 --> 00:13:51.000 At point five the creative teaching aspect comes into full play for student 00:13:51.000 --> 00:13:55.001 participation includes all the follow-up activities which round out your purpose 00:13:55.001 --> 00:14:01.000 in using the film. Discussion, testing for content, research work, report 00:14:01.000 --> 00:14:06.001 writing, problem solving, any or all of these post-film activities plus many many 00:14:06.001 --> 00:14:09.000 more that you will think of are your contribution. 00:14:11.001 --> 00:14:15.000 And it is your contribution which is the single most important factor in 00:14:15.000 --> 00:14:16.001 using a classroom film.